Global occurrence, drivers, and ecological risk of pesticide contamination in lakes

Pesticide contamination poses a major threat to freshwater ecosystems, yet a global synthesis for lakes is lacking. We analyzed a dataset of 139 pesticides from 9069 sites across 291 lakes to characterize contamination patterns, associated factors, and ecological risk. Concentrations varied by orders of magnitude across countries, reaching a maximum of 30.9 ng/L in surface water (Spain) and 22.0 ng/g dry weight in sediment (China). While water concentrations increased with national development levels, sediment concentrations showed the opposite trend, revealing a complex contamination dynamic. Hotspots were identified across North and South America, Africa, and Asia. Pesticide levels were primarily associated with agricultural intensity, climatic factors, and lake morphometry. Ecologically, 84.9 % of surface water sites posed high risk, whereas sediment risk was negligible. The prevalence of high-risk sites was inversely related to national development, indicating that development level correlates with broader socioeconomic and regulatory contexts rather than serving as a direct cause. Continental stratification confirmed that observed patterns are robust across regions, with insecticides dominating risk in Asia, South America, and Africa, while Europe and North America exhibited more diversified profiles reflecting stricter regulations. Our findings underscore that pesticide pollution jeopardizes global ecosystem integrity. This undermines progress toward United Nations Sustainable Development Goals, including zero hunger, good health and well-being, clean water and sanitation, and life below water. Effective management must integrate agricultural practices, lake characteristics, and socioeconomic contexts to mitigate this pervasive threat.